Temporomandibular Disorders (TMD) Practice Exam

Muscle spasms most often come from factors that affect the whole body, not just a single injured muscle. When hydration, electrolytes, and overall metabolic balance are off, nerves and muscles become more excitable, leading to involuntary contractions. Dehydration can alter fluid and electrolyte levels, while electrolyte disturbances—like low potassium, calcium, or magnesium—directly disrupt the way muscles contract. Systemic conditions such as endocrine, kidney, or liver problems, and medications that affect fluid and electrolyte balance, can all predispose to widespread cramps. Because these influences are body-wide, they explain spasms across many different people and situations. Local injuries tend to produce cramps in the specific muscle involved, but they don’t account for the common, generalized occurrence seen with systemic factors.